Clinical Outcomes With Definitive Treatment of Methicillin-Resistant Staphylococcus aureus Bacteremia With Retained Daptomycin and Ceftaroline Combination Therapy vs De-escalation to Monotherapy With Vancomycin, Daptomycin, or Ceftaroline

Abstract

Abstract Background Lower mortality has been observed with combination therapy compared to monotherapy for methicillin-resistant Staphylococcus aureus (MRSA) bacteremia; however, there is a lack of evidence for continued combination therapy over de-escalation to monotherapy following bacteremia clearance. Methods This was a single-center, retrospective study evaluating patients with MRSA bacteremia hospitalized from November 1, 2011, through July 31, 2019. Patients who received three to ten days of combination therapy followed by de-escalation to monotherapy were directly compared to patients retained on combination therapy. The primary composite outcome included inpatient infection-related mortality, 60-day readmission, and 60-day bacteremia recurrence. Results A total of 286 patients with MRSA bacteremia were identified, with 146 patients omitted based on exclusion criteria. The study population included 66 in the combination therapy group and 74 in the monotherapy group. Study population was 51% female (n = 71) and 78% white (n = 109) with median age of 46 years (IQR 34.5–61). No significant difference was observed in the primary composite outcome (21% combination therapy group vs 24% monotherapy group; P =.66), with retained observations after controlling for confounders. Within this outcome, there was no significant difference in 60-day readmission (20% combination therapy group vs 18% monotherapy group; P =.75), bacteremia recurrence (3% combination therapy group vs 7% monotherapy group; P =.45), or inpatient infection-related mortality (2% combination therapy group vs 5% monotherapy group; P = 1.00). Conclusions No difference was found in the composite outcome of 60-day bacteremia recurrence, readmission, or inpatient infection-related mortality for patients with MRSA bacteremia retained on combination therapy versus those de-escalated to monotherapy.